BOOKS OF THE TIMES

By John Gross

Published: September 23, 1986

THE FISHER KING. By Anthony Powell. 256 pages. W. W. Norton. $15.95.

A GROUP of passengers are embarking on an educational cruise that is to take them round the British Isles, putting in at various points of archeological interest. One of them, Valentine Beals, a prolific author of historical romances, has already come aboard, and is leaning over the side watching the new arrivals. In particular, he is looking out for a couple whose names have leaped up at him from the passenger list, the celebrated society photographer Saul Henchman and his assistant and constant companion Barberina Rookwood.

Although Beals has never met them, there can be no mistaking the pair as they come into view on the quay. Not only does Henchman have a camera swinging round his neck; his crutches and the scars that pit his face testify to the damage he sustained during World War II when his patrol car was hit by a shell. Barberina, in dramatic contrast, is young, graceful, ethereally beautiful. They make a strange couple, all the more so since everything suggests that Henchman's wartime injuries left him emasculated. Yet from the moment they met, while she was still in her teens, Barberina fell under his spell, immediately going to live with him and giving up what had promised to be a brilliant career as a dancer.

The cruise ship is called the Alecto, and since Alecto, in Greek mythology, is the name of one of the Furies, it is plain from the outset that we are going to be sailing in fairly deep waters. At dinner on the second night Beals clinches the voyage's mythic possibilities when he overhears Henchman talking about a fishing expedition he had once planned. At least, he thinks he overhears him -the speaker is out of his line of vision, and he can't be quite certain who he is. But that doesn't hinder him from deciding that Henchman is a re-embodiment of one of the most mysterious figures in Arthurian legend, the Fisher King.

The next day he enlarges on his theory for the benefit of his wife and the friends who are traveling with them. The Fisher King, he reminds them, was the maimed and impotent ruler of a barren country - fishing was the only pastime left to him, though if the young warrior Perceval, who encountered him on his wanderings, had had the wit to ask him the right questions, his wound would have been cured and the fertility of his lands restored.

Beals's friends are unimpressed. They start picking holes in the analogy, and Beals himself is forced to admit that it has some obvious imperfections. In what sense, for example, can Henchman's ''kingdom'' - his trade as a photographer - be said to be barren? On the contrary, it seems to be positively thriving. Yet Beals refuses to abandon his idea, and when Henchman and Barberina become caught up in an emotional crisis he does his best to interpret it in terms of Arthurian parallels.

''The Fisher King'' is the first full-length novel Anthony Powell has published since he completed his masterly 12-volume sequence ''A Dance to the Music of Time'' in 1975. It is a curious confection, very different in some respects from Mr. Powell's previous books. If the narrative of ''The Music of Time'' is often highly stylized, it remains basically realistic; ''The Fisher King,'' on the other hand, is a Chinese puzzle in which the author half describes events and half reports Beals's account of them, in which Beals's version is not necessarily to be relied on (though it sometimes turns out to more dependable than at first appears), and in which we are very much left to work out the final significance of the story for ourselves.

Whatever we make of it, the Fisher King motif is too insistent to be set aside as no more than playful embroidery. Yet it is still possible, much of the time, to treat the book as an account of what actually happens on the Alecto, of the complicated game that is played out between Barberina, Henchman, a newspaper tycoon called Gary Lamont, a fierce young woman called Lorna Tiptoft (who may or may not be a modern counterpart of the Arthurian Loathly Damsel), and a young man called Jilson who is not quite as feeble as he looks (he has ''the tenacious will of the indulged child'').

At this level ''The Fisher King'' is for the most part engaging and entertaining. True, it has its failures - the go-getting Gary Lamont, for example, is weirdly implausible in a way that can hardly have been intended. But it also features some comic creations that are perfect of their kind -a seedy old toper called Mr. Jack, for example; and at the center of the action the sardonic, harsh-tongued Henchman is a truly memorable grotesque. (At one stage of his career he was nicknamed ''The Monkey,'' but as Beals observes, ''he hasn't any of the monkey's innate pathos'' - in fact a complete lack of pathos is ''one of his outstanding characteristics.'') The book also gives us a fresh chance to savor Mr. Powell's irony and urbanity, and his dexterous turns of phrase. The pleasures of his prose may not be entirely unmixed - every so often he indulges in a mock-pomposity that comes dangerously close to real pomposity; but his faults are of minor consequence in comparison with the witty precision with which he can sum up a situation, or the melancholy undertones he can impart (without any sacrifice of humor) to scenes that in the hands of a lesser writer would yield straightforward satire or farce.

That having been said, ''The Fisher King'' remains an enigma. Is it a fiction about fiction, a jeu d'esprit with some somber implications, a parable about the ways in which any human transaction can be read in archetypal terms - but only up to a point? It is, at all events, not a book for newcomers to Mr. Powell's work to start with; but for anyone who has already succumbed to the spell of ''A Dance to the Music of Time'' it can hardly fail to have considerable fascination.